Photoelectric regulating and safety burner control system



May 25, 1948. w, RAY

PHOTOELE'CTRIC nseumwme AND SAFETY BURNER cou'rnob SYSTEM Filed June 3, 1946 lno'eutor: VlLLIAM A. RAY,

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Patented May 25, 1948 UNITED s'rn'rrzs PATENT OFFICE.

PHOTOELECTBIC BEGULATING SAFETY BURNER CONTROL SYSTEM William A. Bay, North Hollywood, Calif casino:

to General Controls 00., Glendale, Call! a corporation of California Application June 3, 194 Serial No. 674,060

Claims. (01. res-117.1)

This invention relates to photoelectric regu-- lating and safety burner control system and more particularly to one which includes means for regulating the pressure of gaseous fuel delivered to a burner under the control of a valve.

The present invention may be characterized as an improvement on the system disclosed in my copending application Serial No. 511,436, filed November 23, 1943, wherein an impedance device. the value or setting of whichis varied in accordance with variation of pressure of gas delivered by a throttling valve to a main burner, is arranged to control (through an amplifier) the degree of energization of an electromagnet urging the throttling valve toward open position against the force of a closing bias so as to efiec't regulation of the outlet pressure; a safety feature of the system residing in the provision of means, in circuit with a thermostat normally controlling on-and-ofi operation of the valve, for efiecting closure of the valve in the event of extinguishment of the flame of a pilot burner for igniting the main burner.

An object of the present invention is to provide unitary means combining the regulating and safety functions of the prior invention described in the preceding paragraph; this object being accomplished by the provision of photoelectric means, illuminated by the flame of the pilot burner, for energizing the electromagnet, and gas-pressure responsive means for varying the illumination of the photoelectric means (and thereby the energization of the electromagnet) in accordance with variation of the pressure, the arrangement being such that the valve is closed upon extinguishment of the pilot-burner flame.

For full understanding of this invention, andfurther appreciation of its objects and advantages, reference is to be had to the following detailed description and accompanying drawing, and to the appended claims.

The single figure of the drawing is an elevation, partly in section and in diagram, of a. burner control system embodying the invention.

Generally indicated in the drawing by the numeral i0 is a valve comprising a casing ll having an inlet chamber l2 and an outlet chamber i3 separated by a partition M. This partition has a cylindrical port therethrough, a portion of the partition being raised around the port to form a circular valve seat It. Cooperable with seat It is a two-part closure member H, the up.- per part iii of which is in the form of a. disk of magnetizable material, the lower part I! being 2 a. disk from the underside of the central portion of which there extends an annulus 20 which is a sliding fit in the port l5. This annulus is provided with a plurality of notches 2| through which, when'the closure member is raised from its seat, fluid can pass from inlet l2 to outlet I3; the flow capacity of the valve increasing progressively as the closure member is raised, due especially to the tapering form of the upper end of the ,notches. The upper and lower parts of the closure member are secured together by suitable means (not shown), and between them is the medial portion ofa flexible diaphragm 22 which is clamped at its margin between the top surface of casing II and the flange of a housing 23, which housing covers an opening through the top wall of the casing around the valve seat l6.

Attached to the top wall of housing 23 is an electromagnet, generally indicated at 24; which comprises a U-shaped core 25 having at the end of each of its side arms an enlarged pole-piece 26. Around each side arm of the core is an energizing coil 21, these coils being interconnected in series-aiding relation and having leads which extend to terminal posts 28. The electromagnetis adapted, when energized, to attract the closure member H, the upper part IQ of which constitutes an armature; the extent of upward movement of the closure member being determined by the resultant of the forceproduced by the electromagnet and the opposing force exerted by a pair of springs 29 compressed between the closure member and the pole-pieces 2B-the flow capacity of the valve thus being proportional to the degree of energization of the electromagnet. Recesses 30 are provided in the armature i8 for receiving the lower ends of the springs 29, thedepth of the recesses. being such as to permit direct engagement of the armature with the pole-pieces when the electromagnet is sufllciently energized. A restricted opening- 3|, extending completely through the closure mem-- ber near its periphery, permits communication of fluid between the inlet of the valve and the chamber above the closure member and diaphragm 22; the pressure of the fluid tending to stabilize movement of the closure member in operation.

The valve Ill is adapted to control supply of gas through a conduit 32 to a main burner 33; a. pilot burner 34, for igniting the main burner, being connected by a pipe 35 to the inlet chamber of the valve. Connected in the conduit between the valve and the main burner is a pressure responsive device 36 comprising a casing 31 a portion Of the top wall of which is formed by a flexible diaphragm 38 clamped at its margin to the casing by the flange of a. housing 39 secured to the casing. Mounted on the back wall of this housing is a photocell 40, of conventional type, which is arranged to receive light from the flame 4| of the pilot burner, the light being concentrated on the photocell by means of a lens 42 mounted in an opening through the side wall of the housing. Preferably, the arrangement is such that the photocell'is not influenced by light fromthe flame of the main burner. Secured to the central portion of the diaphragm 38 is a support 43 for a vane or mask which is adapted to penetrate or move across the path of illumination (indicated by the broken lines 45) of the photocell when gas pressure is applied to the, underside of diaphragm 38. This diaphragm is urged downwardly by the force of a spring 46 the tension of which can be adjusted by manipulation of a screw 41, threaded in the bottom wall of casing 31, to which the lower end of the spring is attached; stop-pins 48, engageable by the mask-support 43, limiting downward movement of the diaphragm and mask.

The electrodes of photocell 40 are connected (by wiring, not shown) to terminals 43 which in turn areconnected by wires 50 to the input oi an electronic amplifier indicated by the legend; the output of this amplifier being connected by wires to the terminals of the electromagnetic valve 10. Automatic on-and-oir control or this valve is effected by a thermostat 52 connected by wires 53 to some suitable point of the amplifier between its input and output; th thermostat being of conventional bimetallic type and arranged to respond to the temperature of a space heated by the main burner 33. The amplifier is of conventional design and is adapted (when the thermostat is closed) to pass current to the electromagnet while the photocell is illuminated by the flame, the degree of energization of the electromagnet being proportional to the amount of light received by the photocell.

As shown in the drawing, the contacts of the thermostat are open so that the valve is deenergizedand closed, and the mask 44 in its lowest position wherein illumination of the photocell is I unobscured;

therefore, when the thermostat subsequently closes in response to demand for heat, the full amount of electrical energy is momentarily supplied to the electromagnet, ensuring initial opening of the valve against the full pressure of the gas acting on the top surface of closure member [1, and the biasing force of springs 29.

The valve therefore tends to open to its full ex I tent, but as gas pressure builds up below the diaphragm 38 of the pressure responsive device the mask 44 is raised intothe path of illumination of the photocell and the energization of the electromagnet consequently decreased, so that the valve closure is arrested in a throttling position corresponding to the desired pressure ior which the device 36 is adjusted; any variation of the pressure being compensated for by the resultant change of position of the mask and variation of energization of the electromagnet. In the event of extinguishment of the pilot-bumer flame, the valve closes due to the absence of illumination of the photocell. I

The embodiment of my invention herein shown and described is obviously susceptible of modification without departing from the spirit of the in- 1. In a burner control system: a main burner; a conduit for supplying gas to said main burner;

a throttling valve in said conduit for controlling flow therethrough; an electromagnet for operating said throttling valve; a pilot burner for igniting said main burner; photoelectric means, influenced by the flame of said pilot burner, for energizing said electromagnet; and means, responsive to the pressure of the gas in said conduit, for so varying the illumination of said photoelectric means by said flame that the flow capacity of the valve is varied to compensate for variation of said gas pressure.

2. In a burner control system: a main burner; a conduit for supplying gas to said main burner; a throttling valve in said conduitior controlling flow therethrough; an electromagnet for so oper- I of the valve is reduced with increase of said gas pressure.

3. In a burner control system: a main burner; a conduit for supplying gas to said main burner;

a throttling valve in said conduit for controlling flow therethrough; an electromagnet for so operating said throttling valve that the, flow capacity of the same is a function of the degree of energization of the electromagnet; a pilot burner for igniting said main burner; photoelectric means for energizing said electromagnet and including a photocell illuminated by the flame of said pilot burner; means movable in response to variation of the pressure of the gas in said conduit between the valve and the main burner; and masking means movable in the path' of illumination of said photocell and so operated by said pressure responsive means that the energization of the electromagnet is varied in accordance with variation of said gas pressure.

4. In a burner control system: a main burner; a conduit for supplying gas to said main burner; a throttling valve in said conduit for controlling flow therethrough and biased to closed position; an electromagnet for urging said throttling valve toward open position, so that the flow capacity of the valve is determined by the resultant of the biasing force and the electromagnetic force; a pilot burner for igniting said main burner; photoelectric means for energizing said electromagnet and including a photocell illuminated by the flame of said pilot burner, the arrangement being such that energization of the electromagnet is decreased with decrease of illumination of the photocell; means movable in response to variation of gas pressure in said conduit between the valve and the main burner; and a mask carried by said presssure responsive means and arranged to move across the path of illumination of said photocell so as to vary the energization of the electromagnet by the photoelectric means in accordance with variation of said gas pressure, said mask beconduit for supplying gas to said main burner;

a throttling valve insaid conduit for controlling flow therethrough and biased to closed position; an electromagnet for urging said throttling valve toward open position, so that the flow capacity of the valve is determined by the resultant of the biasing force and the electromagnetic force; a pilot burner for igniting said main burner; a photocell arranged to be illuminated by the flame of said pilot burner; a pressure responsive device connected to said conduit at the outlet side of said valve and comprising a casing having a wall subjected to, and movable in response to variation of, the pressure of the gas supplied to the main burner; a, mask carried by said movable wall and arranged so to move across the path of illumination of said photocell that increase of gas pressure-effects decrease of the illumination; and an electrical'amplifier connecting said photocell to said electromagnet and so designed that energization ofthe electromagnet is decreased with decrease of illumination of the photocell, whereby upon ex- 39 WILLIAM A. RAY.

REFERENCES crrEn The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,602,092 Witz Oct. 5, 1926 1,796,239 Byles -1 Mar. 10, 1931 1,809,280 Knowles June 9, 1931 1,855,551 Jackson Apr. 26, 1932 2,007,714 Gauger July 9, 1935 FOREIGN PATENTS Number Country Date 443,570 Great'Britain Feb. 27, 1936 

